Age of onset as predictor of cognitive performance in children with seizure disorders

This proposed study seeks to examine the influence of the age of onset of seizure activity on cognitive ability in children and adolescents with seizure disorders independent of the duration of the disorder. Both age of onset and duration of disorder have been found, in previous studies, to predict course and prognosis of cognitive deficits in children with epilepsy (O'Leary, 1993; Upton & Thompson, 1997). Specifically, this study will examine the predictive value of age of onset of the seizure activity on scores of a standardized test of intelligence (IQ) after statistically controlling for the number of years (duration) in which the children have had recurring seizure activity. The study will also compare the predictive strength of duration of seizure activity with that of age of onset on cognitive scores by running separate regressions with each as an independent variable. It is hypothesized that the age of onset will continue to be a statistically significant predictor of cognitive ability after removing the influence of duration of seizure activity. Furthermore, it is believed that age of onset will be more strongly correlated with intellectual ability than duration of the seizure activity. Age of onset is expected to positively correlate with standardized tests scores, with lower ages of onset predicting lower IQ scores.